fix: isolate session channels when model storage is off, add override SHARE_CHANNELS_ACROSS_WINDOWS

Author: hhaensel

src/Stipple.jl

@@ -21,6 +21,7 @@ const ALWAYS_REGISTER_CHANNELS = RefValue(true)
 const USE_MODEL_STORAGE = RefValue(true)
 const PRECOMPILE = RefValue(false)
 const FIXED_TYPES = Dict{Module, Vector{Symbol}}()
+const SHARE_CHANNELS_ACROSS_WINDOWS = RefValue{Union{Bool, Nothing}}(nothing)
 
 import MacroTools
 import Pkg.TOML
@@ -29,6 +30,17 @@ function use_model_storage()
   USE_MODEL_STORAGE[]
 end
 
+"""
+Whether windows in the same session should reuse the same channel.
+
+If set to `nothing`, the default follows `use_model_storage()`:
+- `true` => share channels across windows
+- `false` => keep channels isolated unless explicitly enabled
+"""
+function share_channels_across_windows()::Bool
+  SHARE_CHANNELS_ACROSS_WINDOWS[] === nothing ? use_model_storage() : SHARE_CHANNELS_ACROSS_WINDOWS[]
+end
+
 """
 Disables the automatic storage and retrieval of the models in the session.
 Useful for large models.
@@ -458,7 +470,9 @@ function channeldefault(::Type{M}) where M<:ReactiveModel
 
   model_id = Symbol(Stipple.routename(M))
 
-  # Look up channel from session - session persistence should work regardless of model storage
+  # Default channel sharing follows the model storage policy, but may be overridden explicitly.
+  share_channels_across_windows() || return nothing
+
   if use_model_storage()
     stored_model = Stipple.ModelStorage.Sessions.GenieSession.get(model_id, nothing)
     stored_model === nothing ? nothing : getchannel(stored_model)
@@ -597,12 +611,12 @@ function init(t::Type{M};
   channel === nothing && (channel = channelfactory())
   setchannel(model, channel)
 
-  # Store model or channel in session based on model storage setting
+  # Store model or channel in session based on model storage setting and explicit cross-window sync override.
   if use_model_storage()
-    # Store full model when model storage is enabled
+    # Store full model when model storage is enabled.
     Stipple.ModelStorage.Sessions.store(model)
-  else
-    # When model storage is disabled, only store the channel for session persistence
+  elseif SHARE_CHANNELS_ACROSS_WINDOWS[] === true
+    # When model storage is disabled but cross-window sync is explicitly on, store only the channel.
     model_id = Symbol(Stipple.routename(M))
     channel_key = Symbol(string(model_id) * "_channel")
     Stipple.ModelStorage.Sessions.GenieSession.set!(channel_key, channel)

test/runtests.jl

@@ -383,6 +383,32 @@ end
     @test get_channel(s3) != get_channel(s1)
     @test get_channel(s4) == get_channel(s5) == get_channel(s6)
 
+    current_storage = Stipple.use_model_storage()
+    current_channel_sharing = Stipple.SHARE_CHANNELS_ACROSS_WINDOWS[]
+
+    Stipple.enable_model_storage(false)
+    empty!(COOKIE_JAR.entries)
+
+    s7 = string_get("http://localhost:$port/")
+    s8 = string_get("http://localhost:$port/")
+    s9 = string_get("http://localhost:$port/", cookies = false)
+
+    @test get_channel(s8) != get_channel(s7)
+    @test get_channel(s9) != get_channel(s7)
+
+    Stipple.SHARE_CHANNELS_ACROSS_WINDOWS[] = true
+    empty!(COOKIE_JAR.entries)
+
+    s10 = string_get("http://localhost:$port/")
+    s11 = string_get("http://localhost:$port/")
+    s12 = string_get("http://localhost:$port/", cookies = false)
+
+    @test get_channel(s11) == get_channel(s10)
+    @test get_channel(s12) != get_channel(s10)
+
+    Stipple.enable_model_storage(current_storage)
+    Stipple.SHARE_CHANNELS_ACROSS_WINDOWS[] = current_channel_sharing
+
     @clear_cache
     down()
 end